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At least 523 records · Page 29Linked to original sources
PubMed2001

Digitization, analysis and processing of dental images during root canal preparation with Quantec Series 2000 instruments.

AIM: The aim of this study was to determine the shaping ability of Quantec Series 2000 nickel-titanium instruments in the mesio-buccal roots of maxillary first molars and the mesial roots of mandibular first molars. METHODOLOGY: A total of 20 canals were prepared with Quantec instruments, adopting the technique recommended by the manufacturer. Each canal was sectioned horizontally into four and the canal in each portion photographed before and after preparation. The images obtained were digitized and the increase in canal surface for each quadrant of the four sections was evaluated, along with the variation in centre of mass after instrumentation. RESULTS: Mechanical instrumentation of the canals generated mean centre of mass displacements that did not vary between sections, except for the mid-apical section, which showed significant mesial displacement, i.e. toward the side opposite the furcation. Thus, overall, the widening of the canal was symmetrical. CONCLUSIONS: Under the conditions of the study, the Quantec Series 2000 rotary system was simple and safe to use, and created good three-dimensional mechanical preparation of natural canals.

Confidence Intervals↗
PubMed2001

Coronal leakage following three obturation techniques.

AIM: To compare coronal bacterial and India ink leakage in three different obturation techniques with the smear layer having been removed. METHODOLOGY: Seventy extracted single-rooted teeth were instrumented to an apical preparation size 7 Profile Series 29 (Tulsa Dental Products, Tulsa, OK, USA). The smear layer was removed and 20 teeth were randomly obturated with lateral compaction, 20 teeth with vertical compaction, and 20 teeth with Thermafil (Tulsa Dental Products, Tulsa OK, USA). Ten teeth were used for positive (five teeth) and negative (five teeth) controls. Teeth were stored for 90 days in 100% humidity, then subjected coronally to Proteus vulgaris for 21 days to assess bacterial leakage. Following bacterial challenge, India ink was placed coronally for a further 21 days, then scored according to depth of dye leakage. RESULTS: Vertical compaction leaked significantly less than lateral compaction during bacterial challenge. However, when dye was used there were no significant differences. CONCLUSIONS: Bacterial leakage and dye leakage demonstrated considerable variability. The use of a dye following bacterial testing may highlight the failure of experimental devices and vertical root fractures, thus avoiding false positive results found with bacterial testing alone.

Carbon↗
PubMed2001

The influence of preparation technique and sodium hypochlorite on removal of pulp and predentine from root canals of posterior teeth.

AIM: To test the null hypothesis that removal of pulp tissue and predentine from root canals of multirooted teeth is not significantly different when performed by one of two mechanical preparation techniques in conjunction with either water or 3% sodium hypochlorite (NaOCl) irrigation. METHODOLOGY: Forty-six freshly extracted premolar or molar teeth, with pulps vital at the time of extraction, were assigned to four groups balanced by anatomy (group 1, step-back filing/NaOCl; group 2, step-back filing/water; group 3, automated rotary/NaOCl; group 4, automated rotary/water). Preparation was undertaken by a single operator and the volumes of irrigant recorded for each tooth. One root from each tooth was prepared for transverse histological assessment at eight levels, including one at and two apical to the working length. A validated index was used to measure the presence and location of residual pulp tissue and predentine. RESULTS: No statistically significant differences were found in the frequency with which residual pulp tissue or predentine were observed amongst the groups. Coronal parts were more frequently devoid of pulp tissue and predentine than the apical. Canals were frequently occluded with residual pulp tissue apical to the working length. There was a trend for better pulp and predentine removal in accessible parts of the canal as a function of rotary preparation and NaOCl irrigation. The isthmus had residual pulp tissue less frequently in the NaOCl groups. Accessory anatomy was unaffected regardless of technique or irrigant. CONCLUSIONS: Pulp tissue and predentine removal were not significantly different between a step-back filing and an automated rotary preparation technique in conjunction with water or NaOCl.

Bicuspid↗
PubMed2002

Hemisection for treatment of an advanced endodontic-periodontal lesion: a case report.

AIM: To emphasize the importance of primary endodontic treatment when dealing with endo-perio lesions and to demonstrate the considerable healing potential of the endodontic aspect. CASE REPORT: After several years of unsuccessful symptomatic periodontal treatment, an advanced endo-perio lesion on a right-mandibular first molar was successfully treated by root-canal treatment and hemisection after the re-evaluation of the lesion. This successful treatment appeared to have a positive effect on the patient's general well-being. KEY LEARNING POINTS: The origin of a combined endo-perio lesion is indicated by its clinical and radiographic appearance. The periodontal situation is often misinterpreted. The prognosis for the endodontic element of treatment is excellent. Local pathologic processes in the oral cavity may affect a patient's general health.

Female↗
PubMed2002

Periapical health related to the quality of coronal restorations and root fillings.

AIMS: To evaluate the impact of the quality of coronal restorations scored on a clinical and radiographic basis and the quality of root fillings on periapical health. METHODOLOGY: Periapical radiographs were taken of 745 root-filled teeth, randomly selected from patients attending the Ghent University Dental School. The teeth had not received restorative treatment in the previous year. The coronal status was scored both clinically according to modified Ryge's criteria, and radiographically by evaluating the presence of signs of marginal leakage or decay. The quality of the root filling was scored according to criteria of length and homogeneity and the periapical status was categorized on the basis of presence or absence of radiographic signs of apical periodontitis. The relationship between coronal status, quality of root filling and periapical health was determined. The data were analyzed using Chi2 test, Odds ratio, Spearman's r(S) and logistic regression. RESULTS: Thirty-three percent of the teeth had apical periodontitis as diagnosed radiographically. Teeth with good and poor coronal restorations scored clinically had apical periodontitis in 31.1 and 36.8%, respectively; this difference was not statistically significant. The quality of the coronal restorations scored radiographically had a statistically significant influence on the periapical condition (P<0.001) with apical periodontitis in 23.8 and 49.1%, respectively, for acceptable and unacceptable restorations. Marginal decay did not influence the periapical status. Teeth restored without a base under the coronal filling had apical periodontitis in 41.3%, whereas teeth with a base had significantly less (P<0.005) apical periodontitis (25.9%). Composite-restored teeth exhibited apical periodontitis in 40.5% of cases whilst amalgam-restored teeth had apical periodontitis in 28.4% of cases; this difference was statistically significant (P<0.01). Root-canal posts had no influence on periapical health. The length and homogeneity of the root-canal fillings had a significant influence (P<0.01 and P<0.001, respectively) on the presence of apical periodontitis, as well as the quality of the coronal restoration scored radiographically (P<0.001). CONCLUSION: The importance of a good coronal restoration, as well as of a good root filling should be emphasized as the technical quality of both influencing the periapical status.

Belgium↗
PubMed2002

An in vitro investigation into the effects of retained coronal dentine on the strength of a tooth restored with a cemented post and partial core restoration.

AIM: This study aimed to examine the fracture resistance of teeth restored with cast post and partial cores supported by different heights of coronal tooth structure. METHODOLOGY: Four specimen groups were prepared. Group A was the control and consisted of 10 single-rooted teeth restored with post and cores cemented in dowel channels with no retained coronal dentine.The test groups, B, C and D differed in the amount of retained buccal coronal dentine having 3, 4 and 5 mm, respectively. All groups were tested to failure using an Instron Universal Testing Machine, Model 1195. The mode of failure for representative specimens for each group was recorded photographically. RESULTS: Specimens in group B where the remaining dentine core was 3 mm in height fractured at a higher force than specimens in the control group (P = 0.0239). There were no statistically significant differences in the forces required to fracture teeth with retained buccal coronal dentine cores of 4 and 5 mm when compared to the control. There was no statistically significant difference between forces required to fracture groups B and C or groups B and D. CONCLUSION: In this in vitro study, 3 mm of retained coronal buccal dentine improved fracture resistance of teeth restored with partial post and cores when compared to teeth without retained coronal dentine.

Analysis of Variance↗
PubMed1997

Facial talon cusps.

This is a report of two patients with isolated facial talon cusps. One occurred on a permanent mandibular central incisor; the other on a permanent maxillary canine. The locations of these talon cusps suggests that the definition of a talon cusp include teeth in addition to the incisor group and be extended to include the facial aspect of teeth.

Adolescent↗
PubMed1998

Root abnormalities, talon cusps, dentes invaginati with reduced alveolar bone levels: case report.

This is a case report of a Caucasian female who presented with an unusual combination of dental anomalies: short roots on the maxillary central incisors and premolars, talon cusps, dentes invaginati, low alveolar bone heights, tubercles of Carabelli on the maxillary first and second permanent molars, with pyramidal root morphology in three of the second permanent molars. None of the anomalies alone are particularly uncommon but they have not previously been reported together. The occurrence of the anomalies is probably incidental as the conditions are aetiologically unrelated.

Abnormalities, Multiple↗
PubMed2000

Simultaneous occurrence of unusual odontodysplasia and oligodontia in the permanent dentition: report of a case.

Odontodysplasia is an uncommon clinicopathological condition with a variety of expressions. Although it is generally recognized as a localized disorder of dental tissue, its aetiology has not yet been well explained. In the present case, odontodysplasia with oligodontia in the permanent dentition is reported. The patient was in good health with normal stature and no other physical abnormalities. His parents and siblings were dentally and medically normal. The primary teeth appeared to be normal except for the primary second molars, where the enamel was malformed. However, the permanent incisors that had erupted into the oral cavity showed rough and hypoplastic enamel. An orthopantomogram showed 17 congenitally missing permanent teeth and malformation of the other 11 permanent teeth and tooth-germs. Because these findings were caused by developmental disturbances of both the mesodermal and ectodermal dental components, we diagnosed the present case as odontodysplasia accompanied by oligodontia in the permanent dentition.

Anodontia↗
PubMed2002

Pyogenic granuloma subsequent to injury of a primary tooth. A case report.

This paper shows a case of pyogenic granuloma occurring as a post-traumatic oral lesion, in a 19-month-old patient. The palatally chamfered fracture of a maxillary primary incisor together with the continuous sucking of a dummy could have caused the special shape of the pyogenic granuloma over the remaining coronal fragment.

Accidental Falls↗
PubMed2002

Unusual presentation of talon cusp: two case reports.

Talon cusp is an uncommon odontogenic anomaly comprising of an accessory cusp-like structure, usually observed on the palatal surfaces of maxillary incisors. Two uncommon presentations of talon cusp, occurring on a mandibular incisor and on a supernumerary tooth in the maxilla, are reported.

Child↗
PubMed2003

Unusual manifestations in X-linked amelogenesis imperfecta.

This paper describes a female with X-linked amelogenesis imperfecta (XAI). This case is unusual in having taurodontism, pulpal calcifications, coronal defects prior to tooth eruption and unerupted teeth. These findings have been reported in some cases of autosomal dominant and autosomal recessive AI but have not previously been documented in XAI.

Adolescent↗
PubMed2002

Sites of dental erosion are saliva-dependent.

Acid demineralization of teeth causes occlusal erosion and attrition and associated non-carious cervical lesions at sites relatively unprotected by saliva. Associations of occlusal pathology and cervical lesions were looked for in 450 patients with toothwear, and 174 subjects with cervical lesions were identified. Associations of occlusal attrition, or erosion, or no wear, with cervical lesions at 72 buccal and lingual sites were recorded from epoxy resin replicas of the subjects' dentitions (3241 teeth). Criteria used to discriminate occlusal erosion from attrition; and shallow from grooved and wedge-shaped cervical lesions were delineated by scanning electron microscopy (SEM). In the absence of occlusal pathology, cervical lesions were very rare (<1%). In the presence of occlusal pathology, cervical lesions were present in 27.71% of buccal sites as opposed to 2.61% of lingual sites. The commonest site of cervical lesions was the facial of maxillary incisors (36% of sites). The least common site was the lingual aspect of mandibular molars (1.7% of sites). These differences may reflect the normal protective role of serous saliva and salivary pellicle in a site-specific manner, on the lingual surfaces of mandibular teeth particularly, and do not support abfraction as the prime aetiology of cervical lesions.

Adult↗
PubMed2001

Accuracy of the Third Molar Eruption Predictor in predicting eruption.

OBJECTIVE: To evaluate the possibility of applying the Third Molar Eruption Predictor to all panoramic radiographs. STUDY DESIGN: Panoramic radiographs were retrospectively analyzed from a 4-year follow-up study of third molars carried out at the University of Copenhagen, Denmark. The radiographs, taken at a mean age of 20.6 years, included 45 unerupted or partially erupted mandibular third molars in 28 subjects. Because the device was calibrated both with simple proportions and by use of the methods of Bayes' Decision Theory, the separation point of the device was therefore adjusted at 12 mm from the distal surface of the second molar. RESULTS: The predictions of future eruption or impaction made with the calibrated device and the actual clinical outcome 4 years later were in conformity for 80% of the mandibular third molars. CONCLUSION: The Third Molar Eruption Predictor may be applied to all panoramic radiographs, but it seems to require calibration before use.

Adult↗
PubMed2002

Inferior alveolar nerve injury related to mandibular third molar surgery: an unusual case presentation.

Perforation of the lower third molar roots by the inferior alveolar nerve is uncommon and can be difficult to determine by conventional radiographic methods. Presented is a case of perforation that was treated by coronectomy, and showed an unusual complication in that the retained root erupted, moving the canal with it. The radiographic assessment of root perforation and the imaging modalities used to assess such cases are discussed.

Adult↗
PubMed2002

A comparative study of odontogenic keratocysts associated with and not associated with an impacted mandibular third molar.

OBJECTIVE: The purpose of this study was to compare odontogenic keratocysts associated with and not associated with an impacted mandibular third molar. STUDY DESIGN: Panoramic radiographs of odontogenic keratocysts associated with impacted mandibular third molars (15 cysts, associated group) were compared with radiographs of odontogenic keratocysts not associated with impacted mandibular third molars (25 cysts, nonassociated group). The radiographic images were analyzed with reference to the patients' age and sex. RESULTS: The mean age of patients in the associated group was lower than that of patients in the nonassociated group. The mean area of the cysts in the associated group was larger than that of those in the nonassociated group. The patients' ages did not significantly correlate to the areas of either kind of cyst. CONCLUSIONS: The odontogenic keratocysts in the associated group had a tendency toward rapid growth in the patients' youth.

Adolescent↗
PubMed2001

A reliability study of clinical tooth wear measurements.

STATEMENT OF PROBLEM: Most studies examining tooth wear severity have been performed on dental casts. This indirect approach has limited applicability to dental practice because during the assessment of the casts, the identification of dentin exposure is difficult or even impossible. PURPOSE OF STUDY: The purpose of this study was to assess occlusal and incisal tooth wear clinically to determine the reliability of the assessment procedure and to establish the influence of selected relevant clinical variables (dental quadrant, tooth type, and severity of wear) on the reliability. MATERIAL AND METHODS: Forty-five volunteers (17 men, 28 women; mean age 33.7 +/- 10.7 years), 32 with temporomandibular disorders and 13 free from signs and symptoms of such disorders, were evaluated on 4 occasions. Two trained observers graded tooth wear at 2 different points in time with a 5-point ordinal scale developed for use in this study. The inter-rater and intra-rater reliability of the scale was expressed as Cohen's kappa. The influence of 2 clinical variables, dental quadrant and tooth type, on the values of kappa was tested with 1-way analysis of variance and post hoc Bonferroni tests. Probability levels of P< .05 were considered statistically significant. The influence of the final clinical variable, severity of wear, was assessed qualitatively. RESULTS: The overall values of the inter-rater and intra-rater reliability were substantial (kappa = 0.632 to 0.678). The clinical variable dental quadrant did not influence the kappa values, whereas the inter-rater reliability during the first session was better for incisors and canines than for premolars (1-way analysis of variance: F(3,23)=4.577, P=.012; post hoc Bonferroni tests: P=.030 and.036). Qualitative assessment of severity of wear indicated that the more advanced the tooth wear, the more reliably it could be graded. CONCLUSION: By means of the developed 5-point ordinal scale and within the limitations of this study, it was concluded that tooth wear can be assessed reliably in the clinical dental setting.

Adult↗